JP2015096741A - Shift range switching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shift range switching device capable of performing fail-safe control suitable for the case of occurrence of instantaneous interruption of a power source supplied to the electronic control-type shift range switching device.SOLUTION: When a shift range switching device is restarted due to the occurrence of instantaneous interruption of a power source supplied to the shift range switching device, a rotational position of a detent plate 3 is controlled by determining a target shift range on the basis of the rotational position of the detent plate 3 detected by a detent position sensor 14 immediately after the restarting of the shift range switching device.

Description

  The present invention relates to an electronically controlled shift range switching device that drives an actuator to switch the shift range of an automatic transmission, and in particular, when a power supply supplied to the shift range switching device is interrupted, a fail-safe operation is performed. The present invention relates to a shift range switching device capable of performing control.

In recent years, electronically controlled shift range switching devices that drive an actuator incorporating an electric motor to switch the shift range of an automatic transmission have been put into practical use.
In such a shift range switching device, a shift range setting means (generally an input operation unit called “shift lever”, “selector lever”, etc.) for a driver to perform a shift range switching operation and a shift Because there is no mechanical connection with the range switching mechanism (a mechanism that mechanically slides and displaces the manual spool valve that switches the hydraulic circuit in the automatic transmission according to the shift range selected by the driver) The degree of freedom of the vehicle mountability of the shift range setting means is increased.
In addition, since the structure of the shift range setting means can be designed freely, for example, there are a wide range of shift range setting means excellent in ergonomics such as “touch panel”, “push button”, and “jog lever”. It has been adopted.

  In such a shift range switching device, the actuator is operated so that the actual shift range matches the required shift range according to the required shift range output from the shift range setting means when the driver performs the shift range switching operation. Therefore, when switching the shift range, the required shift range (target shift range) and the actual shift range (actual shift range), which is the result of controlling the actuator, are controlled. It goes without saying that one piece of information is extremely important.

An electronically controlled shift range switching device normally operates by receiving power from an in-vehicle battery or the like, so that the power supply may be lost due to some unexpected factor (for example, unexpected contact failure of electrical wiring). There is a possibility that a momentary interruption of power (instantaneous power interruption) may occur.
In the conventional mechanical shift range switching device, the shift range is switched by the driver's operating force via a mechanical transmission mechanism such as a shift cable or shift rod. The shift range (target shift range) set by switching the mechanical shift lever and the actual shift range (actual shift range) realized by operating the shift range switching mechanism reliably match. .
However, in the electronically controlled shift range switching device, since there is no mechanical connection between the shift range setting means and the shift range switching mechanism, the target shift when restarted due to a momentary power interruption The information indicating the range or actual shift range may be lost, and it may not function properly.

Therefore, for example, in Patent Document 1, a storage device that does not lose data even if the power supply is momentarily interrupted (nonvolatile storage device that can retain data even when the power supply is turned off) is employed, and the output shaft position of the actuator (actual shift range) Position information) is always stored, and “if the shift range switching device is restarted due to a momentary power interruption, the electric motor is not driven before the momentary power interruption. Control is continued using the output shaft position of the actuator stored in the non-volatile storage device. ”Or“ On the condition that the electric motor is not driven before the instantaneous power interruption, the non-volatile storage device The stored actuator output shaft position is determined as the range request value output from the shift range setting means, and the control is continued. " Safe control has been proposed.

In recent years, momentary input devices such as “touch panel”, “push button”, and “jog lever” have been increasingly used for shift range setting means for a driver to perform a shift range switching operation. For example, Patent Document 2 discloses a touch range that employs a touch panel as the shift range setting means, and is displayed on the touch panel as D range (forward travel range), N range (non-travel range), and R range (reverse travel). Range), P range (non-running range and parking lock operation), and touching the part where each symbol is displayed lightly with your fingertip, the shift range selected by the driver is output as the required shift range from the shift range setting means It is like that.
For this reason, at least the required shift range must be electrically stored until the actual shift range matches the required shift range after the required shift range is output by the shift range setting means. is there.

  However, when the shift range switching device is restarted due to a momentary power interruption, the information indicating the required shift range may be lost and the function may not function normally. Similarly to the above, it is necessary to employ a non-volatile storage device and always store information indicating the required shift range. As a result, even if a restart due to a momentary power interruption occurs, control can be continued using the requested shift range stored in the nonvolatile storage device.

JP 2006-336840 A JP 2000-240774 A

The fail-safe control proposed in Patent Document 1 can be executed when the electric motor is not driven before the instantaneous power interruption. However, the instantaneous interruption of the power supply does not occur only when the electric motor is not driven, but is expected to occur even while the electric motor is being driven. Therefore, if the power supply is momentarily interrupted while the electric motor is being driven, that is, during shift range switching control, the proposed fail safe is not executed, and the actual shift range becomes indefinite and control is impossible. Or may be erroneously controlled to a shift range not selected by the driver.
In addition, since the nonvolatile storage device has a limited number of data rewrites, it is necessary to select a more reliable specification in order to cope with frequent data rewriting, which increases costs. .

  The present invention has been made in view of the above-described problems, and the purpose thereof is that an instantaneous power interruption occurs in an electronically controlled shift range switching device that drives an actuator to switch the shift range of an automatic transmission. It is another object of the present invention to provide a shift range switching device that can realize fail-safe control suitable for a low cost when the shift range switching device is restarted.

  The shift range switching device according to the present invention is detected by the detent position sensor immediately after the restart when the shift range switching device is restarted due to an instantaneous interruption of the power supplied to the shift range switching device. The target shift range is determined according to the rotational position of the detent plate, and shift range switching control is continued.

  The present invention provides a rotational position of a detent plate detected by a detent position sensor immediately after the restart when the shift range switching device is restarted due to an instantaneous interruption of the power supplied to the shift range switching device. Accordingly, the target shift range is determined in accordance with the shift range, and the shift range switching control is continued. Therefore, it is possible to provide a fail-safe suitable for restarting.

It is a whole block diagram for demonstrating the outline | summary of the shift range switching apparatus which concerns on Embodiment 1 of this invention. It is an enlarged view of a detent plate for demonstrating operation | movement of the detent plate in the shift range switching apparatus which concerns on Embodiment 1 of this invention. It is an expanded view of the detent plate in the shift range switching apparatus which concerns on Embodiment 1 of this invention. It is an expanded view of the detent plate in the shift range switching apparatus which concerns on Embodiment 1 of this invention. It is a flowchart for demonstrating the control method of the shift range switching apparatus which concerns on Embodiment 1 of this invention.

Embodiment 1 FIG.
The electronically controlled shift range switching device determines a shift range (required shift range) selected by the driver as a target shift range, drives an actuator, and is mounted on an automatic transmission (not shown). By changing the operating positions of the switching mechanism and the parking switching mechanism, the hydraulic controller in the automatic transmission is switched to an oil passage corresponding to the target shift range, and the shift range of the automatic transmission is switched.

Hereinafter, preferred embodiments of the shift range switching device according to the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram for explaining an outline of a shift range switching device according to the present invention. In FIG. 1, the actuator 1 includes an electric motor (not shown) and a speed reducer (not shown) that decelerates and outputs the rotation of the electric motor. The rotary shaft 2 joined so as to extend the output shaft is taken out of the actuator 1.

A detent plate 3 having a substantially fan shape is attached to the rotary shaft 2. When the rotary shaft 2 rotates by a predetermined angle by driving the actuator 1, the joint between the rotary shaft 2 and the detent plate 3 is pivoted. As a center, the detent plate 3 also changes its rotational position by a predetermined angle.
A plurality of recesses are provided in the arc portion of the detent plate 3, and an engagement portion 4 a provided at the tip of the detent spring 4 fixed to the hydraulic controller 7 corresponds to the rotational position of the detent plate 3. The rotational position of the detent plate 3 is held by fitting in any one of the plurality of recesses.

Next, the operation of the detent plate 3 configured as described above will be described in detail with reference to FIG.
FIG. 2 is an enlarged view of the detent plate 3. The arcuate portion of the substantially fan-shaped detent plate 3 is provided with four concave portions 3a, 3b, 3c, and 3d, and the engaging portion 4a at the tip of the detent spring 4 is positioned at the rotational position of the detent plate 3. Accordingly, the rotational position of the detent plate 3 is maintained by fitting in any one of the four concave portions 3a, 3b, 3c, and 3d.
The four recesses provided in the detent plate 3 are generally 3a: P range (non-running range and parking lock operation), 3b: R range (reverse running range), 3c: N range (non-running range) ) 3d: Designed in advance as rotational positions for the automatic transmission to realize each shift range of the D range (forward travel range).

  A pin 5 for moving the shift range switching mechanism 6 is attached to the side surface of the detent plate 3. This pin 5 is engaged with the left end portion of the shift range switching mechanism 6. When the detent plate 3 is rotated by the rotation of the rotating shaft 2, the pin 5 is driven in an arc and is engaged with the pin 5. The shift range switching mechanism 6 performs a linear motion (movement in the direction of a double arrow C in FIG. 2) within the hydraulic controller 7.

  In the state shown in FIGS. 1 and 2, the engagement portion 4 a at the tip of the detent spring 4 fits into the recess 3 d provided at the rightmost end of the substantially fan-shaped arc portion of the detent plate 3 to detent. The rotational position of the plate 3 is held, and in this state, the shift range switching mechanism 6 is pushed most shallowly into the hydraulic controller 7, and the oil for realizing the D range is provided in the hydraulic controller 7. The road is constructed and the automatic transmission is controlled to the D range.

  From the above state where the automatic transmission can be controlled to the D range, when the rotary shaft 2 is rotated by a predetermined angle clockwise (clockwise) in the double arrow D in FIG. When the rotational position of the detent plate 3 changes, the engaging portion 4a at the tip of the detent spring 4 comes out of the D-range recess 3d and moves to the N-range recess 3c provided on the left side. Hold the rotation position. In this state, the shift range switching mechanism 6 is pushed into the hydraulic controller 7 by a predetermined amount deeper than the previous D range, and an oil passage for realizing the N range is provided in the hydraulic controller 7. As a result, the automatic transmission can be controlled in the N range.

  From the above state where the automatic transmission can be controlled to the N range, when the rotary shaft 2 is further rotated by a predetermined angle clockwise (clockwise) in the double arrow D in FIG. When the rotational position of the detent plate 3 changes, the engaging portion 4a at the tip of the detent spring 4 comes out of the concave portion 3c for the N range and moves to the concave portion 3b for the R range provided on the left side. Hold the rotation position. In this state, the shift range switching mechanism 6 is pushed further into the hydraulic controller 7 by a predetermined amount deeper than in the previous N range, and the oil path for realizing the R range in the hydraulic controller 7. Thus, the automatic transmission can be controlled in the R range.

  From the above state where the automatic transmission can be controlled to the R range, when the rotary shaft 2 is further rotated by a predetermined angle clockwise (clockwise) in the double-headed arrow D in FIG. As the rotational position of the detent plate 3 changes, the engaging portion 4a at the tip of the detent spring 4 comes out of the concave portion 3b for the R range and moves to the concave portion 3a for the P range provided on the left side. Hold the rotation position. In this state, the shift range switching mechanism 6 is pushed into the hydraulic controller 7 deeper by a predetermined amount than in the previous R range, and an oil passage for realizing the P range is provided in the hydraulic controller 7. The automatic transmission can be controlled to the P range.

In this manner, the shift range switching mechanism 6 is sequentially pushed into the hydraulic controller 7 via the detent plate 3 so that the oil passage in the hydraulic controller 7 is in the D → N → R → P range. As a result, the shift range of the automatic transmission can be controlled in the order of D → N → R → P range.
When the rotary shaft 2 is rotated in the opposite direction, that is, in the counterclockwise direction (counterclockwise) of the double-headed arrow D in FIG. 2, the shift range switching mechanism 6 is now moved via the detent plate 3. By pulling out from the inside of the hydraulic controller 7, the oil passage in the hydraulic controller 7 is switched in the order of P → R → N → D range. As a result, the shift range of the automatic transmission is changed from P → R → N →. Control is possible in the order of the D range.

  As described above, the shift range switching mechanism 6 is driven by the rotation output of the actuator 1 to switch the shift range of the automatic transmission. Each shift range (P, R, N, D range) of the automatic transmission is changed. Is switched by sliding the shift range switching mechanism 6 provided in the hydraulic controller 7 to a position corresponding to each shift range, and switching the oil passage in the automatic transmission.

  It should be noted that the N range and the P range are different in position when the shift range switching mechanism 6 is slid and displaced, but both constitute an oil passage for non-travel. However, in the case of the P range, in addition to the operation of the shift range switching mechanism 6, a parking switching mechanism (a generic name of mechanisms configured by reference numerals 8 to 13) described later is operated. This parking switching mechanism is a mechanism that interlocks with the shift range switching mechanism 6 and mechanically locks the output shaft of the automatic transmission when the actual shift range is set to the P range.

Switching between locking and unlocking of the output shaft of the automatic transmission by the parking switching mechanism is performed by engaging and disengaging the concave portion 13a of the parking gear 13 and the convex portion 11a of the parking pole 11.
The parking gear 13 is connected to the output shaft of the automatic transmission via a drive shaft (not shown), a differential gear (not shown), and the like, and the output shaft of the automatic transmission is controlled by restricting the rotation of the parking gear 13. The side (the drive wheel side of the vehicle) is locked, and the locked state of the parking of the vehicle is achieved.

On the other hand, a parking rod 8 for driving the parking pole 11 is attached to the detent plate 3, and a conical member 9 is provided at the tip of the parking rod 8.
The conical member 9 is interposed between the protruding portion 10 of the housing of the automatic transmission and the parking pole 11, and the concave portion of the detent plate 3 that fits the engaging portion 4 a at the tip of the detent spring 4. When moving from the recess 3b to the recess 3a, that is, when switching from the R range to the P range, the parking rod 8 is displaced in the direction of the arrow A in FIG. 11 is pushed up. Then, the parking pole 11 rotates in the direction of arrow B in FIG. 1 about the parking pole shaft 12 that rotatably holds the parking pole 11, and any of the convex portion 11 a of the parking pole 11 and the concave portion 10 a of the parking gear 13 is detected. One of them is engaged, and the locked state of the parking switching mechanism is achieved.

  When the concave portion of the detent plate 3 fitted to the engaging portion 4a at the tip of the detent spring 4 moves from the concave portion 3a to the concave portion 3b, that is, when switching from the P range to the R range, the detent plate 3 Thus, the parking rod 8 is pulled back in the direction opposite to the direction of the arrow A in FIG. 1, and the force by which the conical member 9 pushes up the parking pole 11 is lost. Then, the parking pole 11 is always urged in the direction opposite to the direction of the arrow B in FIG. 1 by a spring (not shown), so that the convex portion 11a of the parking pole 11 and the concave portion 13a of the parking gear 13 are The engagement is released, the parking gear 13 is freed, and the parking switching mechanism is unlocked.

Next, the configuration and function of the electronic control system in the shift range switching device will be described with reference to FIG.
As components of the electronic control system of the shift range switching device, in addition to the actuator 1, the detent position sensor 14, the actual shift range determination means 15, the shift range setting means 16, the target shift range determination means 17, and the actuator control means 18 are provided. Can be mentioned.
The detent position sensor 14 is a detection means that outputs a signal corresponding to the actual rotation angle position Rang of the detent plate 3, and generally a detection element using the Hall effect is employed.
The actual shift range determination means 15 receives the actual rotation angle position Rang of the detent plate 3 detected by the detent position sensor 14, and the actual shift range Rsft is set to P, R, N based on the actual rotation angle position Rang. The D range is determined and output.
The shift range setting means 16 is an input device that employs the aforementioned “touch panel” or the like, and outputs a requested shift range when operated by the driver.
The requested shift range output from the shift range setting unit 16 is input to the target shift range determining unit 17, and the requested shift range is determined and output as the target shift range Tsft. Further, the target rotational angle position Tang of the detent plate 3 corresponding to the determined target shift range Tsft is calculated and output.
The actuator control means 18 is determined by the actual rotation angle position Rang of the detent plate 3 detected by the detent position sensor 14, the actual shift range Rsft determined by the actual shift range determination means 15, and the target shift range determination means 17. The target shift range Tsft and the target rotation angle position Tang are input.

The actuator controller 18 starts driving the actuator 1 based on the actual rotation angle position Rang and the target rotation angle position Tang of the detent plate 3 so that the actual rotation angle position Rang matches the target rotation angle position Tang. When the actual shift range Rsft matches the target shift range Tsft, the driving of the actuator 1 is stopped.
In this way, the actual shift range of the automatic transmission is switched to the requested shift range selected by the driver.

Next, the normal shift range switching operation will be described with reference to the detent plate development view of FIG.
FIG. 3 shows the actual rotation angle position Rang of the detent plate 3 detected by the detent position sensor 14, the actual shift range Rsft determined by the actual shift range determination means 15, and the target determined by the target shift range determination means 17. Development view of the detent plate 3 shown to explain the relationship between the shift range Tsft and the target rotation angle position Tang (the actual detent plate 3 has the rotation axis 2 as an axis, as shown in FIG. Although it has a substantially fan shape, it is a plan view with the rotation angle as the horizontal axis). For convenience, the state when the engaging portion 14a of the detent spring 4 is engaged with the concave portion 3a and the concave portion 3d of the detent plate 3 is indicated by 4aa and 4ad.

  The horizontal axis of FIG. 3 shows the rotational angle position of the detent plate 3, and the four recesses 3a, 3b, 3c, and 3d for fitting with the engaging portion 4a provided at the tip of the detent spring 4 are The positional relationship is the same as in FIGS. Accordingly, if the engaging portion 4a is located at a rotation angle position of 5 [deg], which is the rotation angle position indicating the recess 3a corresponding to the P range, the detent position sensor 14 uses the actual rotation angle position Rang = 5 [deg] is detected, and the actual shift range determination means 15 determines the actual shift range Rsft = P range.

In determining the actual shift range, the play and variation of each component are taken into account, for example, within the range of ± 2 [deg] with respect to the actual rotation angle position Rang = 5 [deg] of the P range. For example, even if the slide displacement amount of the shift range switching mechanism 6 deviates from the displacement amount corresponding to Rang = 5 [deg], an oil passage for controlling the automatic transmission to a desired shift range can be formed. Therefore, in the control, the range of 5 ± 2 [deg] is set as the P range determination zone. As for the determination of other shift ranges, similarly to the P range determination zone, the R range determination zone is within the range of 15 ± 2 [deg], the N range determination zone is within the range of 25 ± 2 [deg], and 35 ± 2 [deg] ] Is set as the D range determination zone.

  In addition, about 5 [deg] of movable ranges (0 to 5 [deg] and 35 to 45 [deg] at an angular position) are also provided on the outer sides of the recesses 3 a and 3 d that are the recesses at both ends of the detent plate 3. However, these ranges are designed in the case of being controlled from a range other than the P range to the P range, or when being controlled from a range other than the D range to the D range. In addition, the engaging portion 4a of the detent spring 4 does not exceed the left and right restriction walls E beyond this range.

If the actual rotation angle position Rang detected by the detent position sensor 14 is within the range of 3 to 7 [deg], the actual shift range determination means 15 determines the P range as the actual shift range Rsft. In this state, when the driver selects the D range by operating the shift range setting means 16, the D range is output as the required shift range from the shift range setting means 16, and the target shift range determination means 17 outputs the target shift. The range Tsft is determined to be the D range, and the target rotation angle position Tang is determined to be 35 [deg].
As a result, the actuator control means 18 recognizes that a deviation has occurred between the actual rotation angle position Rang and the target rotation angle position Tang of the detent plate 3, and makes the actual rotation angle position Rang coincide with the target rotation angle position Tang. The drive of the actuator 1 is started. As a result, the actual rotation angle position Rang continues to move without stopping during the period from exiting the P determination zone to reaching the D determination zone, and when the actual rotation angle position Rang enters the D determination zone, the actual shift is performed. It is determined that the range Rsft matches the target shift range Tsft, and the driving of the actuator 1 is stopped.
In this way, the actual shift range of the automatic transmission is switched from the P range to the D range selected by the driver.

Next, the development diagram of the detent plate in FIG. 4 shows the problem when the power supply of the shift range switching device is momentarily interrupted and restarted while the electric motor is being driven, that is, while the actual shift range is being changed. It explains using.
In the shift range switching device shown in the overall configuration diagram of FIG. 1, immediately after the power supply is momentarily interrupted and restarted, the microcomputer that controls the electronic control system is reset, so that the driving of the electric motor is stopped, Until then, various information such as the actual rotation angle position Rang and the target shift range Tsft stored in a RAM (Read Only Memory) or the like is initialized and data is lost.
However, since the actual rotation angle position Rang is newly detected by the detent position sensor 14 immediately after the restart, the actual rotation angle position Rang and the actual shift range Rsft determined by the actual shift range determination means 15 are: You can immediately grasp the current value.

However, with respect to the target shift range Tsft and the target rotation angle position Tang, since it becomes impossible to determine which target shift range Tsft the actuator 1 was driven to immediately before the power supply is momentarily cut off, the actual shift range Tsft is indefinite. Thus, normal control cannot be continued, and in some cases, the shift range may be switched to a shift range different from the requested shift range selected by the driver.
Therefore, in the present invention, the target shift range Tsft set before the power supply interruption is calculated based on the actual rotation angle position Rang detected by the detent position sensor 14 immediately after the restart from the power supply interruption. The actual rotation angle position Rang is controlled using the estimated target shift range Tsft.

Hereinafter, based on the actual rotation angle position Rang detected by the detent position sensor 14 immediately after the restart from the power supply interruption, using the development view of the detent plate 3 shown in FIG. The reason why the set target shift range Tsft can be estimated will be described.
4 indicate the positions of the engaging portions 4a provided at the tip of the detent spring 4. The positions of these O symbols are determined by the detent position sensor 14. This is the detected actual rotation angle position Rang. For the symbol O attached with an arrow, the direction of displacement in which the actuator 1 is driven when the target shift range Tsft is switched and the actual rotation angle position Rang is changing toward the target rotation angle position Tang. Is shown.
For the symbol “O” without an arrow, the target shift range Tsft is not switched. Therefore, the actuator 1 is stopped and the actual rotational angle position Rang matches the target rotational angle position Tang and stops. It shows the state.

First, in FIG. 4, the symbol 1A indicates that both the target shift range Tsft and the actual shift range Rsft are in the P range, the actuator 1 is stopped, and the actual rotation angle position Rang is stationary in the P range determination zone. It can be said that it is in a state. Accordingly, in this case, it can be estimated that the target shift range Tsft is the P range based on the rotation angle position Rang. However, in order to determine that the target shift range Tsft is stationary within the P range determination zone, It is necessary to continue to determine that the rotation angle position Rang remains within the P range determination zone.
On the other hand, the symbol 1B in FIG. 4 indicates that the target shift range Tsft is the P range and the actual shift range Rsft is other than the P range, and the actuator 1 is driven to move from the other than the P range toward the P range. It can be said. Therefore, also in this case, it can be estimated that the target shift range Tsft is the P range based on the rotation angle position Rang.
4 indicates that when the actual shift range Rsft is in the P range, the target shift range Tsft is switched to other than the P range, and the actuator 1 is driven to move from the P range to other than the P range. It can be said that it is moving. In this case, it is not possible to estimate whether the target shift range Tsft has been switched to the R, N, or D range only from the actual rotation angle position Rang, but at least the target shift range Tsft before switching (= actual It can be estimated that the shift range (Rsft) was the P range.

As described above, when the actual rotation angle position Rang detected by the detent position sensor 14 immediately after the restart from the momentary power interruption is the symbol 1B in FIG. 4, the target shift range Tsft is detected by the restart. Even if the information related to is lost, since it is possible to estimate that the target shift range Tsft is the P range based on the rotation angle position Rang, the target shift range Tsft is determined to be the P range and the control is continued. In addition, since the range of ○ symbol 1B includes the range of ○ symbol 1A, the rotation angle position Rang is determined to be in the P range continuously for a predetermined period in the description of the state of ○ symbol 1A. The determination of staying in the zone is no longer mandatory.
Further, when the actual rotation angle position Rang detected by the detent position sensor 14 immediately after the restart from the momentary power interruption is the symbol 1C in FIG. 4, the target shift range Tsft after the restart Is difficult to estimate, the P range estimated to have been the target shift range Tsft (= actual shift range Rsft) until immediately before is determined as the target shift range Tsft and control is continued.
As described above, the range of the angular position for determining the P range as the target shift range Tsft based on the actual rotation angular position Rang immediately after the restart is set as the first range.

Next, the symbol 2A in FIG. 4 indicates that both the target shift range Tsft and the actual shift range Rsft are the D range, the actuator 1 is stopped, and the actual rotation angle position Rang is within the D range determination zone. It can be said that it is stationary. Therefore, in this case, it can be estimated that the target shift range Tsft is the D range based on the rotation angle position Rang, but in order to determine that the target shift range Tsft is still within the D range determination zone, It is necessary to continue to determine that the rotation angle position Rang remains within the D range determination zone.
In FIG. 4, the symbol “2B” indicates that the target shift range Tsft is the D range and the actual shift range Rsft is other than the D range, and the actuator 1 is driven to move from the other than the D range toward the D range. It can be said. Therefore, also in this case, it can be estimated that the target shift range Tsft is the D range based on the rotation angle position Rang.
4 indicates that when the actual shift range Rsft is the D range, the target shift range Tsft is switched to other than the D range, the actuator 1 is driven, and the D range is shifted from the D range to the other than the D range. It can be said that it is moving. In this case, it is not possible to estimate whether the target shift range Tsft has been switched to the P, R, or N range only from the actual rotation angle position Rang, but at least the target shift range Tsft before switching (= actual It can be estimated that the shift range (Rsft) was the D range.

As described above, when the actual rotation angle position Rang detected by the detent position sensor 14 immediately after the restart from the power interruption is the symbol 2A or 2B in FIG. 4, the target shift is performed by the restart. Even if information on the range Tsft is lost, since it can be estimated that the target shift range Tsft is the D range based on the rotation angle position Rang, the target shift range Tsft is determined as the D range and the control is continued. . In addition, since the range of ○ symbol 2B includes the range of ○ symbol 2A, the rotation angle position Rang is determined in the D range continuously for a predetermined period in the description of the state of ○ symbol 2A. The determination of staying in the zone is no longer mandatory.
Further, when the actual rotation angle position Rang detected by the detent position sensor 14 immediately after the restart from the momentary interruption of the power supply is the symbol 2C in FIG. 4, the target shift range Tsft after the restart Is difficult to estimate, the D range estimated to have been the target shift range Tsft (= actual shift range Rsft) until immediately before is determined as the target shift range Tsft and control is continued.
As described above, the range of the angular position for determining the D range as the target shift range Tsft based on the actual rotation angular position Rang immediately after the restart is set as the second range.

Next, the symbol 3A in FIG. 4 indicates that both the target shift range Tsft and the actual shift range Rsft are the N range, the actuator 1 is stopped, and the actual rotation angle position Rang is within the N range determination zone. It can be said that it is stationary. Accordingly, in this case, it can be estimated that the target shift range Tsft is the N range based on the rotation angle position Rang. However, in order to determine that the target shift range Tsft is stationary in the N range determination zone, It is necessary to continue to determine that the rotation angle position Rang remains in the N range determination zone, but the range of ○ symbol 3C described later includes the range of ○ symbol 3A. The determination that the rotation angle position Rang remains in the N range determination zone for a predetermined period of time described in the description of the state of the O symbol 3A is not essential.
Next, the state of the symbol 3C in FIG. 4 indicates that when the actual shift range Rsft is the P range or R range, the target shift range Tsft is switched to the N range or D range, the actuator 1 is driven, and P The target shift range Tsft is switched to the P range or R range when the actuator is moving from the range or R range toward the N range or D range, or when the actual shift range Rsft is the N range or D range. It can be said that it is in a state of being driven and moving from the N range or D range toward the P range or R range.
In this case, it is impossible to estimate whether the target shift range Tsft has been switched to the P, R, N, or D range only from the actual rotational angle position Rang. The target shift range is determined and shift range switching control is continued.
As described above, the range of the angular position for determining the N range as the target shift range Tsft based on the actual rotational angular position Rang immediately after the restart is set as the third range.

Next, the symbol 4A in FIG. 4 indicates that both the target shift range Tsft and the actual shift range Rsft are the R range, the actuator 1 is stopped, and the actual rotation angle position Rang is within the R range determination zone. It can be said that it is stationary. Accordingly, in this case, it can be estimated that the target shift range Tsft is the N range based on the rotation angle position Rang, but in order to determine that the target shift range Tsft is stationary within the R range determination zone, It is necessary to continue to determine that the rotation angle position Rang remains within the R range determination zone.
On the other hand, the range of the ○ symbol 3C described above includes the range of the ○ symbol 4A. Therefore, when the operation at the time of the ○ symbol 3C is given priority, both the target shift range Tsft and the actual shift range Rsft are Even if the vehicle is in the R range, the target shift range Tsft will be changed to the N range after the restart, so in order to follow the requested shift range selected by the driver, immediately after the restart. If the actual rotation angle position Rang detected by the detent position sensor 14 is in the R range determination zone, it is determined whether or not the actual rotation angle position Rang is stationary in the R range determination zone. When it is determined that the vehicle is stationary within the R range determination zone, the R range is determined to be the target shift range Tsft and control is continued.

  As described above, when the shift range switching device is restarted due to an instantaneous interruption of the power supplied to the shift range switching device, the shift range switching device according to the present embodiment detents immediately after the restart. The target shift range is determined according to the rotational position of the detent plate detected by the position sensor, and shift range switching control is continued.

  In addition, this shift range switching device is detected by the detent position sensor immediately after the restart when the shift range switching device is restarted due to an instantaneous interruption of the power supplied to the shift range switching device. When the rotational position of the detent plate is within the first range set to the P range side than the predetermined rotational position range for determining the R range, the P range is determined as the target shift range and the shift is performed. Continues range switching control.

That is, when the control state immediately before the momentary power interruption occurs is expected to be one of the following 1A), 1B), and 1C), the P range is determined as the target shift range. To continue shift range switching control.
1A) The target shift range is the P range, and the actual shift range is also the P range.
1B) The target shift range is the P range, and the actual shift range is being controlled from the non-P range to the P range.
1C) The target shift range is other than the P range (however, it is unknown whether the true target shift range is the R range, the N range, or the D range), and the actual shift range is other than the P range to the P range. On the way to being controlled.

  In addition, this shift range switching device is detected by the detent position sensor immediately after the restart when the shift range switching device is restarted due to an instantaneous interruption of the power supplied to the shift range switching device. When the rotational position of the detent plate is within the second range set to the D range side than a predetermined rotational position range that is determined in advance to determine the N range, the D range is determined as the target shift range. Then, the shift range switching control is continued.

That is, when it is expected that the control state immediately before the momentary power interruption occurs is any of the following 2A), 2B), and 2C), the D range is determined as the target shift range. To continue shift range switching control.
2A) The target shift range is the D range, and the actual shift range is also the D range.
2B) The target shift range is the D range, and the actual shift range is being controlled from the other than the D range to the D range.
2C) The target shift range is other than the D range (however, it is unknown whether the true target shift range is the N range, the R range, or the P range), and the actual shift range is other than the D range to the D range. On the way to being controlled.

  In addition, this shift range switching device is detected by the detent position sensor immediately after the restart when the shift range switching device is restarted due to an instantaneous interruption of the power supplied to the shift range switching device. When the rotational position of the detent plate is within a third range set between a predetermined rotational position range for determining the R range and a predetermined rotational position range for determining the N range. , N range is determined as the target shift range, and shift range switching control is continued.

That is, when the control state immediately before the momentary power interruption occurs cannot be predicted and is in the state of 3A) below, the N range is determined as the target shift range and the shift range switching control is continued.
3A) The target shift range is unknown (the target shift range cannot be specified).

  In addition, this shift range switching device is detected by the detent position sensor immediately after the restart when the shift range switching device is restarted due to an instantaneous interruption of the power supplied to the shift range switching device. When the rotational position of the detent plate is within the first range, the P range is determined as the target shift range, and when it is within the second range, the D range is set as the target shift range. If it is within the third range, the N range is determined as the target shift range, and shift range switching control is continued.

  That is, when it is expected that the control state immediately before the momentary power interruption occurs is any one of the above-described 1A), 1B), and 1C), the P range is set to the target shift range. When it is determined and the shift range switching control is continued, and the control state immediately before the momentary power interruption occurs is expected to be one of the above states 2A), 2B), and 2C) When the D range is determined as the target shift range, the shift range switching control is continued, and the control state immediately before the momentary power interruption occurs is expected to be the state of 3C) above. Determines the N range as the target shift range and continues the shift range switching control.

  In addition, this shift range switching device has a detent detected by the detent position sensor immediately after the restart when the shift range switching device is restarted due to an instantaneous interruption of the power supplied to the shift range switching device. If the rotational position of the plate is within a predetermined rotational position range determined in advance for determining the R range (reverse travel range) for a predetermined period, the R range is given priority over the N range. Is determined as the target shift range and shift range switching control is continued.

That is, when it is expected that the control state immediately before the momentary power interruption occurs is the state of 4A) below, the R range is determined as the target shift range and the shift range switching control is continued. .
4A) The target shift range is the R range, and the actual shift range is also the R range.

  According to the shift range switching device according to the present embodiment, when the shift range switching device is restarted due to an instantaneous interruption of the power supplied to the shift range switching device, the detent position sensor immediately after the restart. Since the target shift range is determined according to the rotational position of the detent plate detected by the above and the shift range switching control is continued, a suitable fail safe can be provided when the system is restarted.

  Further, according to the shift range switching device according to the present embodiment, even if the target shift range immediately before the momentary interruption occurs is the P range, the P range is set as the target shift range after the restart. Since it is set, it is possible to provide a failsafe suitable for a restart. If the target shift range immediately before the momentary power failure occurs cannot be specified other than the P range, the target shift range after the restart is the actual value immediately before the momentary power failure occurs. Since the P range expected as the shift range is set, only the requested shift range selected by the driver immediately before is canceled, and at least the erroneous control to the driver's unexpected shift range is avoided. Therefore, it is possible to provide an excellent fail safe that is suitable when restarted.

  Further, according to the shift range switching device according to the present embodiment, even if the target shift range immediately before the momentary interruption occurs is the D range, the D range is set as the target shift range after the restart. Since it is set, it is possible to provide a failsafe suitable for a restart. If it is not possible to determine whether the target shift range immediately before the momentary power interruption occurs is other than the D range, the actual shift immediately before the momentary power interruption occurs as the target shift range after restart. Since the expected D range is set as the shift range, the requested shift range selected by the driver immediately before is canceled, and at the very least it is avoided that the shift range is unexpectedly controlled by the driver. For this reason, it is possible to provide a failsafe suitable for restarting.

  Further, according to the shift range switching device according to the present embodiment, when the target shift range immediately before the momentary power interruption occurs is unknown, the N range is set as the target shift range after restart. Therefore, erroneous control to any one of the ranges P, R, and D can be avoided, and a fail-safe suitable for restarting can be provided.

  Further, according to the shift range switching device according to the present embodiment, even if the actual shift range immediately before the occurrence of a power interruption due to restart is lost in the R range, the target shift range after restart is lost. Since the R range is set, it is possible to provide a fail safe suitable for restarting.

  Further, according to the shift range switching device according to the present embodiment, the adoption of the nonvolatile storage device is not essential for realizing the effects of the above-described inventions, and therefore the shift range switching device can be provided at low cost. .

Next, the control method of the shift range switching device according to the present invention described above will be described with reference to the flowchart of FIG.
In step S101 and step S102, the actual rotation angle position Rang of the detent plate 3 detected by the detent position sensor 14 is read, and the actual shift range Rsft is determined based on the actual rotation angle position Rang.
In the next step S103, it is determined whether or not the shift range switching device has just been restarted. If it is not immediately after the restart (in the case of NO), the process proceeds to step S112. The process proceeds to S104.

If the shift range switching device has just been restarted, in steps S104 and S105, the flag F and the counter C used in this control are cleared to zero, and the process proceeds to step S106.
In step S106, it is determined whether the current restart is a normal restart due to turning on the key switch or an abnormal restart due to a momentary power interruption.
Here, when it is determined that the current restart is a normal restart due to turning on the key switch (in the case of NO), the process proceeds from step S106 to step S114. For example, the determination is made in step S102 above. The actual shift range Rsft is determined as the target shift range Tsft, and the process proceeds to step S121.

In step S121, the state of the flag F is determined. Since the flag F has already cleared F = 0 in step S104, the determination is NO at this time, and the process proceeds to step S122.
In step S122, it is determined whether or not the required shift range due to the driver's operation has occurred. If the required shift range has occurred (in the case of YES), the process proceeds to step S123, and the required shift range is set to the target shift range. The range Tsft is determined and the process proceeds to step S124. On the other hand, if the requested shift range has not occurred (NO), the process proceeds to step S124 without doing anything.
In step S124, the target rotational angle position Tang corresponding to the target shift range Tsft is calculated based on the currently determined target shift range Tsft, and the process proceeds to step S125.

In step S125, it is determined whether or not the actual rotation angle position Rang read in step S101 matches the target rotation angle position Tang calculated in step S124. In this embodiment, for example, a range of ± 2 [deg] (Tang−2 ≦ Rang ≦ Tang + 2) is set as the range determination zone with respect to the target rotation angle position Tang.
In step S125, when the actual rotation angle position Rang is not in the determination zone of the target shift range Tsft (in the case of NO), the process proceeds to step S126, the drive of the actuator 1 is commanded, and the process ends. On the other hand, when the actual rotation angle position Rang is in the determination zone of the target shift range Tsft (in the case of YES), the process proceeds to step S127, the stop of the actuator 1 is instructed, and the process is terminated.

Then, when it is time to execute the next process, the process starts again from step S101. In the same manner as the above-described process, the actual rotation angle position detected by the detent position sensor 14 is again detected in steps S101 and S102. Rang is read, and the actual shift range Rsft is determined based on the actual rotation angle position Rang.
In the next step S103, it is determined whether or not the shift range switching device has just been restarted. However, since this time is not immediately after the restart, the determination is NO and the process proceeds to step S113.
In step S113, the state of the flag F is determined. Since the flag F remains cleared to F = 0, the determination is NO and the process proceeds to step S121.

  Thereafter, the steps from step S121 to step S127 are the same as the above-described processing, and thus the description of each processing is omitted. In summary, when the requested shift range by the driver's operation occurs, The shift range Tsft is updated to the required shift range, the target rotation angle position Tang is calculated, and the drive of the actuator 1 is instructed until the actual rotation angle position Rang reaches the determination zone of the target shift range Tsft. This is the operation from step S121 to step S127.

Next, processing when it is immediately after an abnormal restart due to a momentary power interruption will be described.
First, in the same manner as described above, in steps S101 and S102, the actual rotation angle position Rang of the detent plate 3 detected by the detent position sensor 14 is read, and the actual shift range Rsft is determined based on the actual rotation angle position Rang.
In the next step S103, it is determined whether or not the shift range switching device has just been restarted. However, if it is immediately after an abnormal restart due to a momentary power interruption, a YES determination is made, and step S103 is performed. From step S104 to step S105, the flag F and the counter C used in this control are cleared to zero, and step S106 follows.
When it is determined whether the current restart is an abnormal restart due to a momentary power interruption (in the case of YES), the process proceeds from step S106 to step S107.

In step S107, is the actual rotation angle position Rang read in step S101 within the first range (a range for determining the P range as the target shift range Tsft immediately after restarting due to a momentary power interruption)? If the actual rotation angle position Rang is within the first range (in the case of YES), the process proceeds to step S115, the P range is determined as the target shift range Tsft, and the process proceeds to step S121. .
In step S108, the actual rotation angle position Rang read in step S101 is within the second range (the range for determining the D range as the target shift range Tsft immediately after restarting due to a momentary power interruption). If the actual rotation angle position Rang is within the second range (in the case of YES), the process proceeds to step S116, the D range is determined as the target shift range Tsft, and the process proceeds to step S121. Proceed with
If the actual rotation angle position Rang read in step S101 is neither within the first range nor within the second range, the process proceeds to step S109.
In step S109, the flag F is set to F = 1 for the first time, and the process proceeds to step S110. In step S110, whether or not the actual rotation angle position Rang read in step S101 is outside the R range determination zone. Is determined. Here, the YES determination, that is, the actual rotation angle position Rang read in step S101 is the third range (N range as the target shift range Tsft immediately after restarting due to a momentary power interruption) excluding the R range determination zone. If it is determined that the value is within the range, the process proceeds to step S117, where the N range is determined as the target shift range Tsft, and in steps S119 and S120, the flag used in this control. F and the counter C are cleared to zero, and the process proceeds to step S121.

In step S121, the state of the flag F is determined. The flag F is set both when the P range is determined as the target shift range Tsft (step S114) and when the D range is determined (step S115). Since no operation has been performed, a NO determination is made in step S121, and the process proceeds from step S121 to step S122. Further, also when the N range is determined as the target shift range Tsft (the above step S117), the flag F is cleared to F = 0 by the process of step S119, and therefore, NO determination is made in step S121. The process proceeds from step S121 to step S122.
In step S122, it is determined whether or not the required shift range has been generated by the driver's operation. If the required shift range has occurred (YES), the process proceeds to step S123, and the required shift range is set. The target shift range Tsft is determined and the process proceeds to step S124. On the other hand, if the requested shift range has not occurred (NO), the process proceeds to step S124 without doing anything.
In step S124, the target rotational angle position Tang corresponding to the target shift range Tsft is calculated based on the currently determined target shift range Tsft, and the process proceeds to step S125.

  In step S125, it is determined whether or not the actual rotation angle position Rang read in step S101 matches the target rotation angle position Tang calculated in step S124, and the actual rotation angle position Rang is determined as the target shift range Tsft. If it is not in the determination zone (NO), the process proceeds to step S126 to command the actuator 1 to exit the process. On the other hand, when the actual rotation angle position Rang is in the determination zone of the target shift range Tsft (in the case of YES), the process proceeds to step S127, the stop of the actuator 1 is instructed, and the process is terminated.

Then, when it is time to execute the next process, the process starts again from step S101. In the same manner as the above-described process, the actual rotation angle position detected by the detent position sensor 14 is again detected in steps S101 and S102. Rang is read, and the actual shift range Rsft is determined based on the actual rotation angle position Rang.
In the next step S103, it is determined whether or not the shift range switching device has just been restarted. However, since this time is not immediately after the restart, the determination is NO and the process proceeds to step S113.
In step S113, the state of the flag F is determined. Since the flag F remains cleared to F = 0, the determination is NO and the process proceeds to step S121.

  Thereafter, the steps from step S121 to step S127 are the same as the above-described processing, and thus the description of each processing is omitted. In summary, when the requested shift range by the driver's operation occurs, The shift range Tsft is updated to the required shift range, the target rotation angle position Tang is calculated, and the drive of the actuator 1 is instructed until the actual rotation angle position Rang reaches the determination zone of the target shift range Tsft. This is the operation from step S121 to step S127.

Next, a case will be described in which the actual rotation angle position Rang read in step S101 is in the R range determination zone immediately after an abnormal restart due to a momentary power interruption.
In step S110 described above, when the actual rotation angle position Rang read in step S101 is within the R range determination zone (in the case of NO determination), the process proceeds from step S110 to step S111.
In step S111, it is determined whether or not the counter C used for measuring that the predetermined period has elapsed is equal to or greater than N. Now, assuming that N = 2, the description proceeds. In step S111, it is determined whether or not the counter C is 2 or more. Currently, the counter C has never been incremented, and therefore C = 0 remains. In this step S111, a NO determination is made, the process proceeds from step S111 to step S112, and the counter C is incremented by one. Then, the process proceeds to step S121.
In step S121, the state of the flag F is determined. However, in the present case where the process proceeds from step S110 to step S111, since the flag F remains set to F = 1 in step S109, the process proceeds from step S121 to step S127. Then, a stop command is issued to the actuator 1 and the process is terminated.

Then, when it is time to execute the next process, the process starts again from step S101. In the same manner as the above-described process, the actual rotation angle position detected by the detent position sensor 14 is again detected in steps S101 and S102. Rang is read, and the actual shift range Rsft is determined based on the actual rotation angle position Rang.
In the next step S103, it is determined whether or not the shift range switching device has just been restarted. However, since this time is not immediately after the restart, the determination is NO and the process proceeds to step S113.
In step S113, the state of the flag F is determined. This time, since the flag F is F = 1, the determination is YES, and the process proceeds to step S110. In step S110, again, It is determined whether or not the actual rotation angle position Rang read in step S101 is outside the R range determination zone.
If it is determined in step S110 that the actual rotation angle position Rang is outside the R range determination zone, the actual rotation angle position Rang remains in the R range determination zone for a predetermined period. It is determined that it has not been performed, and the process proceeds from step S110 to step S117. When the process proceeds to S117, as described above, the process of determining the N range as the target shift range Tsft is executed.
On the other hand, if it is determined in step S110 that the actual rotation angle position Rang was not outside the R range determination zone, it is determined that the actual rotation angle position Rang still remains within the R range determination zone. The process proceeds from step S110 to step S111.
In step S111, it is determined again whether the counter C has reached N or more. At present, the counter C is incremented only once and C = 1, so that the determination in step S111 is NO, the process proceeds from step S111 to step S112, and the counter C is further incremented by one. Proceed to

In step S121, the state of the flag F is determined. Since the flag F remains set to F = 1, the process proceeds from step S121 to step S127, a stop command is issued to the actuator 1, and the process ends.
Then, when it is time to execute the next process, the process proceeds again from step S101 → S102 → S103 → S113 → S110, and it is determined that the actual rotation angle position Rang is outside the R range determination zone. Advances from step S110 to step S117, and processing for determining the N range as the target shift range Tsft is executed.
On the other hand, if it is determined in step S110 that the actual rotation angle position Rang was not outside the R range determination zone, it is determined that the actual rotation angle position Rang still remains within the R range determination zone. The process proceeds from step S110 to step S111.
In step S111, it is determined again whether the counter C has reached N or more. At present, the counter C is incremented twice and C = 2, so in this step S111, a YES determination is made, the process proceeds from step S111 to step S118, and the R range is changed to the target shift range Tsft. In step S119 and step S120, the flag F and the counter C are cleared to zero, and the process proceeds to step S121. In step S121 and subsequent steps, processing similar to that described above proceeds with the flag F = 0.

DESCRIPTION OF SYMBOLS 1 Actuator, 2 Rotating shaft, 3 Detent plate, 3a-3d Recessed part, 4 Detent spring, 4a Engagement part, 6 Shift range switching mechanism, 14 Detent position sensor, 15 Actual shift range determination means, 16 Shift range setting means, 17 Target shift range determination means, 18 Actuator control means, Rang actual rotation angle position, Tang Target rotation angle position, Rsft actual shift range, Tsft Target shift range.

Claims (6)

An actuator that outputs the rotation of the electric motor, a detent plate that is rotated by the rotation output of the actuator, and one of a plurality of recesses provided in the detent plate to engage with any one of the recesses. The detent spring that acts to fix the rotational position, and the automatic transmission according to the rotational position of the detent plate when the detent spring is fixed by engagement with the recess provided in the detent plate. A shift range switching mechanism for switching the shift range;
A detent position sensor for detecting position information according to the rotational position of the detent plate;
An actual shift range determining means for determining an actual shift range of the automatic transmission based on position information corresponding to the rotational position of the detent plate detected by the detent position sensor; and a requested shift range corresponding to the operation of the driver. Shift range setting means for outputting;
Target shift range determining means for determining the required shift range output from the shift range setting means as a target shift range;
Based on the position information according to the rotational position of the detent plate detected by the detent position sensor, the actual shift range determined by the actual shift range determination means, and the target shift range determined by the target shift range determination means. An actuator for controlling the rotational position of the detent plate by driving the actuator so that the actual shift range determined by the actual shift range determining means matches the target shift range determined by the target shift range determining means. A shift range switching device comprising a control means,
When the shift range switching device is restarted due to an instantaneous interruption of the power supplied to the shift range switching device, the target shift range determining means is detected by the detent position sensor immediately after the restart. A shift range switching device, wherein a target shift range is determined according to a rotational position of the detent plate.   The target shift range determining means is configured such that the rotational position of the detent plate detected by the detent position sensor immediately after the restart is greater than the rotational position range for determining the R range (reverse travel range) (non-travel range and parking lock). 2. The shift range switching device according to claim 1, wherein the P range is determined as a target shift range when the first range is set to the operation) side.   The target shift range determining means is such that the rotational position of the detent plate detected by the detent position sensor immediately after restarting is closer to the D range (forward travel range) side than the rotational position range for determining the N range (non-travel range). 2. The shift range switching device according to claim 1, wherein if it is within the set second range, the D range is determined as a target shift range.   The target shift range determination means is configured such that the rotational position of the detent plate detected by the detent position sensor immediately after restarting is determined from the predetermined rotational position range for determining the R range (reverse travel range) to the N range (non-travel range). 2. The shift range switching according to claim 1, wherein the N range is determined as the target shift range when the rotation range is within the third range set up to the rotational position range for determining apparatus. An actuator that outputs the rotation of the electric motor, a detent plate that is rotated by the rotation output of the actuator, and one of a plurality of recesses provided in the detent plate to engage with any one of the recesses. The detent spring that acts to fix the rotational position, and the automatic transmission according to the rotational position of the detent plate when the detent spring is fixed by engagement with the recess provided in the detent plate. A shift range switching mechanism for switching the shift range;
A detent position sensor for detecting position information according to the rotational position of the detent plate;
An actual shift range determining means for determining an actual shift range of the automatic transmission based on position information corresponding to the rotational position of the detent plate detected by the detent position sensor; and a requested shift range corresponding to the operation of the driver. Shift range setting means for outputting;
Target shift range determining means for determining the required shift range output from the shift range setting means as a target shift range;
Based on the position information according to the rotational position of the detent plate detected by the detent position sensor, the actual shift range determined by the actual shift range determination means, and the target shift range determined by the target shift range determination means. An actuator for controlling the rotational position of the detent plate by driving the actuator so that the actual shift range determined by the actual shift range determining means matches the target shift range determined by the target shift range determining means. A shift range switching device comprising a control means,
When the shift range switching device is restarted due to an instantaneous interruption of the power supplied to the shift range switching device, the target shift range determining means is detected by the detent position sensor immediately after the restart. The rotational position of the detent plate is
If it is within the first range set to the P range (non-traveling range and parking lock operation) side relative to the rotational position range for determining the R range (reverse running range), the P range is set to the target shift range. Decide
If it is within the second range set to the D range (forward travel range) side than the rotational position range for determining the N range (non-travel range), the D range is determined as the target shift range,
When it is within the third range set between the predetermined rotational position range for determining the R range (reverse traveling range) and the rotational position range for determining the N range (non-traveling range) The shift range switching device characterized by determining the N range as a target shift range. The target shift range determination means is such that the rotational position of the detent plate detected by the detent position sensor immediately after the restart is
If it is within a predetermined rotational position range for determining the R range (reverse running range) continuously for a predetermined period, the R range is determined as the target shift range in preference to the N range. The shift range switching device according to claim 4 or 5, wherein